While camping at Bottomless Lakes State Park outside of Roswell, NM, my girlfriend and I heard a strange, high-pitched, oscillating sound coming from the west. We heard the sound for about 30 seconds and got up from our campsite (out from under some trees) to investigate. The sound was making area coyotes/dogs howl like crazy. The object had a red light on one side and a green light on the other, and white lights on the front and back. The red and green lights were about a third of the way between the white lights-- if you connected the lights, it would look like a kite. So basically, not terribly unlike a plane, but a different shape.

However it did not sound like any plane we'd ever heard. It was traveling relatively slow and low and went directly over us. As it did, due to the Doppler effect, the sound became lower and the oscillations slower. We followed it until it disappeared into the horizon.

We suspected it might be a B-2, but saw one the flying the next day outside of Alamogordo and it did not sound the same at all. Based on subsequent Internet research, we're pretty sure it wasn't one. Actually, as an aside, it sort of sounded like the opening music on the MUFON website (www.mufon.com).